Self contained gas powered surgical apparatus

ABSTRACT

A self contained gas powered endoscopic surgical apparatus is provided for placing lateral lines of surgical fasteners into body tissue. The apparatus includes a frame portion, an elongated portion extending from the frame portion, and an articulating fastener applying assembly associated with a distal end of the elongated portion. The fastener applying assembly includes a base portion, a staple cartridge housing, and an anvil member which has a forming surface thereon against which surgical fasteners are driven as they are ejected from the cartridge housing. A self contained pneumatic system is associated with the frame portion and is actuable to eject the surgical fasteners from the cartridge assembly. A first mechanism is provided for effectuating the rotation of the fastener applying assembly about an axis defined by the body portion, a second mechanism is provided for effectuating the articulation of the fastener applying assembly, and a third mechanism is provided for independently rotating the cartridge housing and anvil member relative to a longitudinal axis defined by the base position to increase the range of operability of the apparatus.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional of U.S. application Ser. No. 08/024,533 filed Mar.1, 1993, now U.S. Pat. No. 5,312,023. This application is acontinuation-in-part of application Ser. No. 07/949,685, filed Sep. 23,1992, now abandoned, which is a continuation-in-part of copendingapplication Ser. No. 07/915,425 filed Jul. 17, 1992, which is acontinuation-in-part of application Ser. No.07/781,012, filed Oct. 18.1991 now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to surgical sampling apparatus, and moreparticularly to surgical apparatus which are powered by self containedrelatively low pressure gas systems to perform sequential operationssuch as tissue clamping, staple forming and/or tissue cutting.

2. Description of Related Art

Surgical sampling apparatus is known wherein tissue is first grasped orclamped between opposing jaw structure and then fastened by means offasteners. In some instruments a knife is provided to cut tissue whichhas been joined. The fasteners are typically in the form of surgicalstaples. However, two part polymeric type fasteners are also known.

Instruments for this purpose can comprise two elongated fingers whichare respectively used to capture or clamp tissue. Typically, one of thefingers carries a disposable cartridge housing wherein a plurality ofstaples are arranged in at least two lateral rows while the other fingercomprises an anvil for curling the staple legs into a hook-likeconfiguration upon their being driven against the anvil. The staplingoperation is effected by a pusher which travels longitudinally along thecartridge carrying finger, with the pusher acting upon the staples toplace rows of staples in body tissue. A knife may be optionallypositioned in such a manner so as to operate sequentially immediatelybehind the pusher, and laterally positioned between the staple rows tolongitudinally cut and/or open the stapled tissue between the rows ofstaples. Such instruments are disclosed in Bobrov et al. (U.S. Pat. No.3,079,606) and Green (U.S. Pat. No. 3,490,675). These instrumentscomprise apparatus for simultaneously making a longitudinal incision andapplying a row of staples on both sides of the incision.

A later development disclosed in Green (U.S. Pat. No. 3,499,591) appliesa double row of staples on each side of the incision. This isaccomplished by a cartridge assembly wherein a cam member moves within aguide path between two sets of staggered staple carrying grooves. Stapledrive members located within the grooves each have two staple pusherplates, and sloping surfaces disposed within the guide path so as to becontacted by the longitudinally moving cam and be driven along thegroove to effect ejection of two staples.

The cartridge assemblies typically come in a plurality of sizes, eachvarying in both length and number of staples contained therein.Depending on the procedure to be performed, the surgeon must select theappropriate cartridge assembly. No provision is currently available toadjust the firing means of the instrument itself so that a wide varietyof staple driving sequences may be accomplished using a single staplecartridge assembly.

The instruments described above were all designed to be used in surgicalprocedures wherein surgeons have direct manual access to the operationsite. However, in endoscopic or laparoscopic procedures surgery isperformed through a small incision or through narrow cannulae insertedthrough small entrance wounds in the skin. In order to address thespecific needs of endoscopic and/or laparoscopic surgical procedures, anendoscopic surgical stapling apparatus such as that shown in Green etal. (U.S. Pat. No. 5,040,715) has been developed. This apparatus is wellsuited for such procedures and incorporates a distal end having an anviland staple cartridge assembly and a manually operated handle assemblyinterconnected by an endoscopic portion which permits the instrument tobe inserted into a cannula and be remotely operated by the surgeon.

The instruments discussed above all require some degree of manuallyapplied force in order to clamp, fasten and/or cut tissue. This manualapplication can prove awkward or difficult depending upon theorientation of the instrument relative to the surgeon, the type oftissue being operated on or the ability of the surgeon to apply thenecessary force. Furthermore, because of the difficulty and expense ofcleaning and sterilizing surgical instruments between uses, there isincreasing interest in and demand for instruments which are disposableafter use in a single surgical procedure rather than permanent andreusable. Self contained gas powered surgical staplers are known, asshown, for example, in U.S. Pat. Nos. 3,618,842; 3,643,851; 3,662,939;3,717,294; 3,815,476 and 3,837,555. Typically, these staplers include areplaceable cylinder which supplies gas (e.g., carbon dioxide ornitrogen) at relatively high pressure (e.g., 800 p.s.i.g.) for poweringthe instrument. The high pressure gas used in these staplers requiresthat the staplers be of relatively heavy construction in order toaccommodate the high pressure involved. Because of their construction,these instruments are relatively expensive to manufacture and thereforeoften intended to be relatively permanent and reusable.

Use of a relatively low pressure gas is advantageous to enable a staplerto be made of lighter construction and less expensive materials. This isdesirable to lower the cost and make the stapler economicallydisposable. The stapler must, however, be capable of generating thesubstantial forces required to form the staples. Typically, the staplesare metal wire which is partially formed prior to use and which must befurther formed (e.g., crimped against an anvil) by the stapler. Togenerate the relatively large forces required to form the staples withlow pressure gas would ordinarily require a relatively large pneumaticactuator. This is undesirable because a large actuator makes the staplerbulky and difficult to work with. In addition, a large actuatorunnecessarily consumes a large amount of gas during the portion ofactuator motion when relatively large forces are not required, i.e.,during the first part of the actuator stroke when the staple is merelybeing advanced to the staple forming position. The gas which is thuseffectively wasted substantially reduces the number of staplingoperations which can be performed by the stapler before its gas supplyis exhausted. This substantially shortens the useful life of the staplerif the gas supply is not replaceable, and even if the gas supply isreplaceable, it undesirably increases the frequency with which the gassupply must be replaced.

Although it may be desirable to perform functions of the staplingapparatus automatically using the self-powering elements in theapparatus, it may also be desirable for the initial function to be atleast partly manual. For example, if the initial function is tissueclamping, it may be preferable to initiate such function manually sothat it can be performed slowly and precisely and the results inspectedand corrected if necessary before the automatic self-powered portion ofthe operating sequence begins. See, for example, U.S. Pat. Nos.4,349,028 and 4,331,277 to Green.

Many of the instruments described above are limited in their range ofoperability. Improvements have been made in the art of surgicalinstruments to increase their range of operability. For example Nierman(U.S. Pat. No. 4,880,015) discloses a biopsy forceps designed for usethrough a flexible fiberoptic bronchoscope. The biopsy forceps includesa handle connected to a thin elongated flexible shaft with a distalportion thereof hinged to the shaft. A grasping tool or biopsy forcepsis attached to the distal hinged portion. Control wires extend from thehandle through the distal to the shaft for controlling the angularrotation of the distal portion of the instrument.

In accordance with these and other principles, it is an object of thepresent invention to provide a self contained gas powered surgicalinstrument for driving surgical fasteners into body tissue whichinstrument has an increased range of operability.

It is another object of the present invention to provide a selfcontained gas powered surgical apparatus insertable through a smallincision or narrow tube for driving surgical fasteners into body tissueand cutting the body tissue between rows of staples.

It is still another object of the present invention is to provide a selfcontained gas powered surgical apparatus which is disposable after use.

Another object of the present invention is to provide a self containedgas powered surgical apparatus having a mechanism which will preventclamping of tissue unless the cartridge has been properly inserted inthe instrument.

Yet another object of the present invention is to provide a selfcontained gas powered surgical apparatus having sealing structure forinhibiting the escape of insufflation gas through the apparatus.

Another object of the present invention is to provide a self containedgas powered surgical apparatus having counter structure for displayingthe number of times the instrument has been fired.

A further object of the present invention is to provide a self containedgas powered surgical apparatus with structure to disable the apparatusafter a predetermined number of firings have occurred.

Another object of the present invention is to provide a surgicalapparatus that provides a full range of remotely actuated movements tothe distal working members of the apparatus to facilitate interactionwith and manipulation of tissue.

SUMMARY OF THE INVENTION

The objects of the invention are accomplished by providing a selfcontained endoscopic surgical instrument which is at least partiallyoperable by means of a relatively low pressure pneumatic assembly. Thesurgical instrument in accordance with an embodiment of the presentinvention is a surgical stapling apparatus which is adapted for placingone or more longitudinal rows of staples. This apparatus may furtherinclude a knife for making an incision in body tissue between the rowsof staples. The latter configuration may find particular use ofadjoining two hollow organs or in removing an organ, such as theappendix, the gallbladder, etc.

In a preferred embodiment of the subject invention the endoscopicstapler comprises a frame portion, an elongated tubular body portionextending from the frame portion and adapted for receiving anarticulating cartridge assembly. The articulating cartridge assemblyincludes a cartridge mounting portion removably maintained in a distalend portion of the tubular body portion and a cartridge housing portionwhich is pivotally connected to the cartridge mounting portion. A cableloop assembly is associated with the tubular body portion of theinstrument for effectuating the articulation of the cartridge housingportion relative to the cartridge mounting portion of the cartridgeassembly. The cable loop assembly includes a cable member, a pivot blockmember mounted for rotation in a distal end portion on the tubular bodyportion about an axis perpendicular to the longitudinal axis thereof,and a rotation control member operatively associated with the tubularbody portion of the apparatus for manipulating the cable loop assembly.A cartridge element, which includes a plurality of surgical staplesslidably mounted therein, and having a tissue engaging surface, isreceivable within the cartridge housing portion of the cartridgeassembly. An anvil member is also provided which has a staple formingsurface formed thereon and which is mounted adjacent the cartridgehousing portion of the cartridge assembly such that the anvil member ismovable between an open position and a closed position wherein thestaple forming surface is in close cooperative alignment with the tissueengaging surface of the cartridge element.

The apparatus further comprises means associated with the tubular bodyportion for moving the anvil member between the open and the closedpositions, and means for ejecting the surgical staples from thecartridge element in such a manner so as to cause the staples to engageand form on the staple forming surface of the anvil member. The meansfor moving the anvil member comprises a linkage mechanism associatedwith the frame portion and extending into the tubular body portion to acable mechanism. The cable mechanism includes a cable member mounted ata leading end thereof to the linkage mechanism and at a trailing endthereof to the cartridge housing portion of the cartridge assembly. Theanvil member is operatively associated with the cable memberintermediate the ends thereof. The means for ejecting the surgicalfasteners comprises a plurality of pusher elements in abutment with thesurgical fasteners, and at least one cam bar for actuating the pusherelements. The cam bar is mounted in an adapter which translates withinthe cartridge assembly. In one embodiment of the cartridge assembly, thecam bar is fixedly mounted in the adapter while in another embodimentthe cam bar is freely movable within the adapter.

The articulating cartridge assembly of the subject invention is alsoprovided with bearing means for guiding the translation of the cam barsas they traverse the cartridge assembly at such times when the cartridgehousing portion of the cartridge assembly is articulated relative to thecartridge mounting portion thereof.

A self contained pneumatic system is disposed in the frame portion ofthe instrument and includes a supply of relatively low pressure gasconnected to a pneumatic actuator mechanism. The pneumatic actuatormechanism actuates the means for ejecting the surgical fasteners fromthe cartridge element. More particularly, the actuator mechanism isoperatively connected to the cam bar adapter. Alternatively, theapparatus may be manually operable by the user.

In another preferred embodiment of the surgical apparatus of the subjectinvention, the instrument includes a fastener applying assembly having abase portion and fastener applying means which include a staplecartridge housing and an anvil member. First means are provided foreffectuating articulation of the fastener applying assembly between afirst position generally in alignment with the longitudinal axis of theelongated body of the instrument and a second position angularlydisposed with respect to the longitudinal axis of the elongated body.Second means are provided for effectuating rotation of the fastenerapplying assembly about the longitudinal axis defined by the elongatedbody relative to the frame portion. Third means are provided foreffectuating independent rotation of the fastener applying meansrelative to the base portion of the fastener applying assembly tofurther increase the range of operability of the surgical apparatus ofthe subject invention.

The surgical apparatus of the subject invention may further comprisesealing means associated with the tubular body portion of the instrumentfor prohibiting the egress of insufflation gas therethrough duringsurgical procedures.

The surgical instrument may be constructed either as a reusable unit oras a single use, disposable unit or, alternatively may be formed with areusable handle portion and replaceable body portions and/or staplecarrying cartridges.

The present invention advantageously permits surgeons to performinternal surgical procedures including stapling and/or cutting simply bymanually clamping the tissue to be manipulated and pneumaticallyactuating the jaw members. This results in greater convenience and easeof use of the instrument as well as more uniform actuation of theinstrument mechanisms.

Further features of the invention, its nature, and various advantageswill become more apparent from the accompanying drawings and thefollowing detailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described hereinbelow withreference to the drawings wherein:

FIG. 1 is a perspective view of a self contained gas powered endoscopicsurgical instrument in accordance with the present invention;

FIG. 2 is an exploded perspective view of the frame and pneumaticassembly of the surgical instrument of FIG. 1;

FIG. 3 is a side plan view in cross section taken along line 3--3 ofFIG. 1 showing the frame and pneumatic assembly in the unclamped andunfired position;

FIG. 4 is a transverse view in cross section taken along line 4--4 ofFIG. 3 oriented toward the proximal end of the instrument showing theframe and pneumatic assembly in the unclamped position;

FIG. 5 is a side plan view in cross section showing the frame andpneumatic assembly in the clamped and unfired position;

FIG. 6 is a transverse view in cross section taken along line 6--6 ofFIG. 5 oriented toward the proximal end of the instrument showing theframe and pneumatic assembly in the clamped and unfired position;

FIG. 7 is a top plan view in cross section taken along line 7--7 of FIG.3 showing the frame and pneumatic assembly of the surgical instrument;

FIG. 8 is a transverse view in cross section taken along line 8--8 ofFIG. 3 oriented toward the distal end of the instrument showing aportion of the frame and pneumatic assembly;

FIG. 9 is a side plan view in cross section showing the frame andpneumatic assembly of the present invention in the clamped and firedposition;

FIG. 10 is a side cut away view in cross section showing the operationof the pneumatic assembly of the present invention as it is fired;

FIG. 11 is a side cut away view in cross section taken along line 11--11of FIG. 10 showing the valve and gas tube of the pneumatic assembly;

FIG. 12 is an exploded perspective view of another embodiment of thehandle portion in accordance with the apparatus of FIG. 1;

FIGS. 13 and 14 are side cross-sectional views of the firing triggerwith integrated lockout structure in the unfired and fired positionsrespectively;

FIG. 15 is an exploded perspective view of the elongated portion of thesurgical instrument of FIG. 1;

FIG. 16 is an exploded perspective view of the articulating cartridgeassembly of the surgical instrument of FIG. 1;

FIG. 17 is a bottom plan view of the anvil member of the articulatingcartridge assembly of FIG. 16;

FIG. 18 is a perspective view of the articulating cartridge assembly ofthe surgical instrument of FIG. 1;

FIG. 19 is a top plan view of the articulating cartridge assembly ofFIG. 18 with the cartridge element removed therefrom;

FIG. 20 is an enlarged perspective view of the external portion of thecam bar adapter shown in FIG. 23;

FIG. 21 is an enlarged perspective view of the internal cam barmaintaining element of the cam bar adapter shown in FIG. 23;

FIG. 22 is an enlarged perspective view, partially cut-away, of the cambar adapter of FIGS. 20 and 21;

FIG. 23 is a top plan view of the cartridge assembly of the FIG. 18showing an adapter for freely maintaining the distal end portions of thecam bars;

FIG. 24 is a top plan view of the cartridge assembly of FIG. 18 showingan adapter for fixedly maintaining the distal end portions of the cambars;

FIG. 25 is an enlarged perspective view of the pivot block illustratedin FIGS. 15 and 16;

FIG. 26 is a side elevational view of the pivot block of FIG. 25;

FIG. 27 is a top plan view in cross-section taken along line 27--27 ofFIG. 26 showing the configuration of the cable passageway definedtherein;

FIG. 28 is an enlarged perspective view, partially cut-away, of thedistal end of the elongated portion of the subject invention showing themechanisms provided therein;

FIG. 29 is a perspective view, partially cut-away, of the surgicalinstrument of FIG. 1 with the anvil member in an opened position;

FIG. 30 is a perspective view, partially cut-away, of the surgicalinstrument of FIG. 1 with the anvil member in a closed position;

FIG. 31 is an enlarged perspective view, partially cut-away, of thecartridge assembly of the apparatus of FIG. 1 in a first articulatedposition;

FIG. 32 is an enlarged perspective view, partially cut-away, of thecartridge assembly of the apparatus of FIG. 1 in a second articulatedposition;

FIGS. 33-35 are top plan views of the cartridge assembly of theapparatus of FIG. 1 in an articulated position illustrating a completefiring sequence wherein:

FIG. 33 illustrates the prefiring position of the cam bar adapter;

FIG. 34 illustrates the cam bar adapter in the fully fired position;

FIG. 35 shows the return stroke of the cam bar adapter within thecartridge assembly;

FIG. 36 is an enlarged perspective view, partially cut-away, of anotherembodiment of the surgical instrument in accordance with the subjectinvention in a first articulated position;

FIG. 37 is a cross-sectional view taken along line 37--37 of FIG. 36;

FIG. 38 is an enlarged perspective view, partially cut-away, of thesurgical instrument of FIG. 36 in a second articulated position;

FIG. 39 is a cross-sectional view taken along line 39--39 of FIG. 38;

FIG. 40 is an enlarged perspective view, partially cut-away, of themechanism for effectuating the articulation of the surgical instrumentof FIG. 36;

FIG. 41 is a cross-sectional view taken along line 41--41 of FIG. 40;

FIG. 42 is a cross-sectional view taken along line 42--42 of FIG. 40;

FIG. 43 is a cross-sectional view taken along line 42--42 of FIG. 40,illustrating a first operational position of the mechanism of FIG. 40;

FIG. 44 is a cross-sectional view taken along line 42--42 of FIG. 40,illustrating a second operational position of the mechanism of FIG. 40;

FIG. 45 is an enlarged perspective view, partially cut-away, of anotherembodiment of the mechanism for effectuating the articulation of thesurgical instrument of FIG. 36;

FIG. 46 is a cross-sectional view taken along line 46--46 of FIG. 45;

FIG. 47 is a cross-sectional view taken along line 47--47 of FIG. 45;

FIG. 48 is a cross-sectional view taken along line 47--47 of FIG. 45,illustrating a first operational position of the mechanism of FIG. 45;

FIG. 49 is a cross-sectional view taken along line 47--47 of FIG. 45,illustrating a second operational position of the mechanism of FIG. 45;

FIG. 50 is an exploded perspective view of yet another embodiment of theactuation member associated with the mechanism for effectuating thearticulation of the surgical instrument of FIG. 36;

FIG. 51 is a side elevational view, partially cut-away, of the actuationmember of FIG. 50;

FIG. 52 is a side elevational view of another preferred embodiment of aself contained gas powered endoscopic surgical instrument in accordancewith the subject invention, the distal end of which has an increasedrange of operability;

FIG. 53 is a top plan view in partial cross-section of the surgicalinstrument of FIG. 52 with the distal end portion thereof in anarticulated position relative to the elongated portion of theinstrument;

FIG. 54 is a top plan view of the surgical instrument illustrated inFIG. 53 with the distal end portion thereof rotated about its own axis;

FIG. 55 is a side elevational view in cross-section of the frame orhandle assembly of the surgical instrument of FIG. 52 with the actuatinghandle thereof in a first position;

FIG. 56 is a side elevational view in cross-section of the handleassembly illustrated in FIG. 55 with the actuating handle thereof in asecond position;

FIG. 57 is a cross-sectional view taken along line 57--57 of FIG. 55;

FIG. 58 is a side elevational view in cross-section of the fastenerapplying assembly of the surgical instrument of FIG. 52 in an openposition;

FIG. 59 is a side elevational view in cross-section of the fastenerapplying assembly of the surgical instrument of FIG. 52 in a closedposition;

FIG. 60 is a cross-sectional view of a planetary gear assembly takenalong line 60--60 of FIG. 52;

FIG. 61 is a cross-sectional view of a planetary gear assembly takenalong line 61--61 of FIG. 52;

FIG. 62 is a side elevational view in partial cross-section of thefastener cartridge removed from the base portion of fastener applyingassembly of the surgical instrument of FIG. 52;

FIG. 63 is a top plan view in partial cross-section of the articulatedjoint at the distal end of the surgical instrument of FIG. 52; and

FIG. 64 is a cross-sectional view of a planetary gear assembly takenalong line 63--63 of FIG. 63.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is generally accepted that endoscopic procedures are more common thanlaparoscopic procedures. Accordingly, the present invention shall bediscussed in terms of endoscopic procedures and apparatus. However, useherein of terms such as "endoscopic", "endoscopically" and "endoscopicportion", among others, should not be construed to limit the presentinvention to a stapling and cutting apparatus for use only inconjunction with an endoscopic tube. On the contrary, it is believedthat the present invention may find use in any procedure where access islimited to a small incision, including but not limited to laparoscopicprocedures. Also, as used herein the terms "fasteners" and "staples"shall be treated equivalently. Unless otherwise stated, the term"cartridge assembly" shall include at least the cartridge itself andstaples or fasteners and staple drive members disposed therein.

In the drawings and the description which follows, as is customary, theterm "proximal" refers to the end which is closest to the operator whilethe term "distal" will refer to the end which is furthest from theoperator.

Referring to FIG. 1, a self contained gas powered endoscopic surgicalapparatus constructed in accordance with the principles of the presentinvention is illustrated and is designated generally by referencenumeral 50. Surgical apparatus 50 essentially comprises a frame portion52 and an elongated portion 54. An anvil member 56 and an articulatingcartridge assembly 58 are preferably removably mounted in a distal endportion 60 of elongated portion 54. Anvil member 56 and cartridgeassembly 58 are manually controlled by means of an articulating handle62 associated with frame portion 52. More particularly, handle 62interconnects with anvil member 56 by means of a linkage and cableassembly which is associated with the elongated portion 54 such thatwhen handle 62 is articulated from an open position (see FIG. 3) to aclosed position (see FIG. 5), anvil member 56 is moved into closeapproximation with the articulating cartridge assembly 58. Thisoperation will be discussed in greater detail hereinbelow.

Turning now to FIG. 2, the frame portion 52 of surgical apparatus 50includes opposed first and second housing members 64 and 66 whichenclose a pneumatic system designated generally by reference numeral 68.The distal end portion of articulating handle member 62 is pivotallyconnected to a clamp tube 70 at a pivot point 72. Longitudinal grooves74 are formed in the opposed first and second housing members 64 and 66adjacent pivot point 72 for slidably receiving molded shuttles 76 whichare attached to the articulating handle member 62 at pivot point 72. Themolded shuttles 76 are pivotally connected to either side of the pivotpoint 72 on the distal end of handle 62 and function to guide the distalend thereof in a longitudinally distal direction as handle 62 isarticulated.

A pair of articulating links 78 interconnect an intermediate portion ofhandle member 62 to a pair of projections 80 formed on an upper surfaceof housing members 64 and 66 respectively. A handle return spring 82extends between handle 62 and housing members 64 and 66 by means of apair of spring anchor pins 84, one of which is disposed in handle 62 andthe other extending between projections 80. Anchor pins 84 also serve topivotally connect articulating links 78 to projections 80. This spring82 assists in returning handle 62 from its closed position to its openposition.

The proximal end of articulating handle 62 is preferably diagonallyformed away from housing members 64 and 66 so as to enable the surgeonto more easily release the handle 62 from its closed position. This isdone by placing the hand under the proximal end of handle 62 andlifting. A texturized or serrated portion 86 may be advantageouslyformed on an under surface of the proximal end of handle 62 to enhancethe gripping thereof.

Pneumatic system 68 is wholly contained within housing members 64 and 66and includes a container 88 of relatively low pressure gaslongitudinally slidably mounted therein. The pressure of the gas incontainer 88 during operation of the stapler is typically less thanabout 200 p.s.i.g. and preferably in the range from about 80 p.s.i.g. toabout 160 p.s.i.g. Any suitable non-toxic gas can be used including butnot limited to halogenated hydrocarbons which are gaseous at roomtemperature, e.g., fluofinated hydrocarbons such as Freon 12 orchlorinated hydrocarbons such as Freon 152A. Container 88 dispenses therelatively low pressure gas through stem 90, valve 92, and gas tube 94when the firing trigger 96 is depressed. Spring 97 is positioned betweencontainer 88 and valve 92 and functions to hold the container 88 in aposition spaced from valve 92. Valve 92 is fixed within housing members64 and 66 and is longitudinally adjustable by means of set screw 93 (seeFIG. 11). This feature permits the position of valve 92 to belongitudinally changed to compensate for manufacturers' variations inlength among containers 88 between a distal end and the proximal end ofstem 90. A pneumatic actuator 98 is disposed above container 88 withinhousing members 64 and 66. Actuator 98 includes a pneumatic cylinder 100which is held in place by opposed pins 99. Cylinder i00 is substantiallyclosed at the proximal end thereof but for a ferrule 102 extendingtherethrough and is open at its distal end, wherein a pneumatic piston104 is mounted for reciprocal motion therein on an axis which isparallel to the longitudinal axis of elongated portion 54. Cylinder 100is preferably circular in transverse cross-section, however, otherconfigurations would function acceptably well.

Piston 104 is pneumatically sealed to cylinder 100 by an O-ring 106molded of polyethylene or the like. Gas dispensed from container 88 issupplied to pneumatic actuator 98 via gas tube 94 which admits the gasto cylinder 100 through ferrule 102 behind piston 104 to drive piston104 distally in the cylinder 100. The distal end of piston 104 isadapted to engage the firing mechanism of the surgical apparatus as willbe described in greater detail below.

Referring to FIGS. 2-10, firing trigger 96 is pivotally mounted in aproximal end of housing members 64 and 66 by a pivot pin 108. A spring110 is positioned adjacent pin 108 which serves to bias firing trigger96 proximally into the prefiring position. A trigger rod 112 extendsdistally from firing trigger 96 in a longitudinal direction so as toengage a piston slide 114 which is positioned in a lower portion ofpiston 104. Piston slide 114 comprises a substantially U-shaped channelwhich fits into a corresponding groove 116 formed in piston 104. Pistonslide 114 is spring loaded in a proximal direction by a spring 118 andincludes a transverse projection 120 on a lower distal end thereof whichengages the distal end of trigger rod 112.

A rocking lever 120 is pivotally mounted on a transverse slide pin 122and is adapted for transverse movement relative to slide pin 122 betweenan engaged position prior to firing (see FIGS. 5-7) and a disengagedposition when articulating handle 62 is open (see FIGS. 3 and 4). A camslide 124 is vertically mounted in first housing member 64 forreciprocal movement between an upper position and lower position (seeFIGS. 4 and 6, respectively). Cam slide 124 functions to move rockinglever 120 between the engaged position (FIG. 6) and the disengagedposition (FIG. 4). Thus, until articulating handle member 62 is closed,causing cam slide 124 to move rocking lever 120 into the engagedposition, surgical instrument 50 cannot be fired.

Cam slide 124 is normally biased in its upper disengaged position by acam slide spring 126 which is mounted in vertical groove 128 formed inthe first housing member 64 (see FIGS. 3 and 4). In this upper position,cam slide 124 extends upward beyond first housing member 64 to engagearticulating handle member 62 as it is moved to a closed position (seeFIGS. 5 and 6). Cam slide 124 further includes a camming surface 130which contacts a corresponding camming surface of a camming block 132which is mounted on slide pin 122. Camming block 132 is loaded againstcam slide 124 by a slide spring 134 and moves rocking lever 120transversely on slide pin 122 between an engaged position and adisengaged position. As articulating handle 62 is compressed towardhousing members 64 and 66 in the direction of arrow 135 it contacts camslide 124, moving it downward, and causing camming surface 130 to movecamming block 132 and rocking lever 120 transversely into an engagedposition in alignment with piston 104.P Turning to FIGS. 3, 5-7 and 9,once the articulating handle 62 has been fully compressed, rocking lever120 is disposed in alignment with piston slide 114 and can be pivotallymoved about transverse slide pin 122 to engage a pusher disk 136disposed at the distal end of container 88. When the instrument is inthe clamped configuration, depression of firing trigger 96 moves triggerrod 112 distally in the longitudinal direction causing piston slide 144to engage and pivot rocking lever 120 which, in turn, engages pusherdisk 136 and moves container 88 into contact with valve 92 to dispensegas and propel piston 104 in the distal direction (see FIGS. 9-11).

As piston 104 moves distally, rocking lever 120 remains in its pivotedfiring position by contact with the bottom surface of piston 104. A gap138 is formed in the bottom surface of piston 104 adjacent the proximalend thereof which effectively allows rocking lever 120 to disengage frompiston 104 and return to a position wherein container 88 is releasedfrom engagement with valve 92, thereby stopping the flow of gas intopneumatic cylinder 100.

A pair of return springs 140 and 142 disposed in elongated portion 54drive piston 104 back to its initial prefired position. A cammingsurface 144 is formed in a distal end of gap 138 which causes rockinglever 120 to move out of engagement with piston 104 as it returns androcking lever 120 moves to its original prefired position (see FIG. 5).

Referring to FIG. 12, another embodiment of frame portion 52 isillustrated which includes annular rings 150 and 152 both of which areprovided between the distal end of frame 52 and the proximal end ofelongated portion 54. In addition to the reduction in egress ofinsufflation gas resulting from the close tolerances and interfitting ofstructural elements within frame portion 52 and/or elongated portion 54,these rings 150,152 further inhibit the escape of insufflation gas fromthe operative site. Additionally, rings 154 and 156 are positionedadjacent the proximal and distal ends, respectively, of clamp tube 70 toeffectively seal off insufflation gas from the area of piston 104.

This embodiment of frame portion 52 further comprises a countermechanism including a counter ratchet 160 attached to trigger rod 112,and a leaf spring 162 which is mounted in housing 66 so as to engageteeth formed on the bottom surface of counter ratchet 160. Numericalindicators are disposed in longitudinal spaced apart relationship on anouter surface of the counter ratchet 160 and correspond to the number oftimes apparatus 50 has been fired. An access plate 164 having a viewingwindow 166 therein is positioned in the outside surface of housingmember 66 to facilitate observation of the counter mechanism.

In operation, each time the instrument is fired the leaf spring 162engages a respective proximally located tooth of the counter ratchet160, effectively sliding the counter ratchet 160 distally to align thenext lower number in viewing window 166. The counter mechanism of thisembodiment further includes a locking feature whereby the trigger button96 is retained in the fired position when the leaf spring 162 engagesthe most proximal surface of the counter ratchet 160 and prevents thefiring rod 112 from returning to its proximal unfired position.

This embodiment of frame portion 52 further includes an integral triggerbutton rotary safety mechanism comprising a rotary safety shaft 168disposed within a roller 170. The rotary safety mechanism is rotatablypositioned in trigger button 96 with the roller 170 extending out beyondthe plane of the back surface of trigger button 96. Projections 172 areeccentrically formed on both sides of rotary safety shaft 168 and extendout beyond the plane of the side surfaces of the trigger button 96. Aspring 174 functions to bias the rotary safety mechanism such thatprojections 172 are disposed in their distalmost orientation.

Referring now to FIGS. 13 and 14, in the instrument's unfired positionprojections 172 are in their distalmost position and are disposed indirect alignment with the proximal ends of the housing members 64 and66. In this position, trigger button 96 cannot be accidentally depressedto fire the instrument. In order to disengage the safety mechanism, theroller 170 is moved in the direction of arrow 176 so as to rotateprojections 172 from their distalmost position to their proximalmostposition effectively allowing trigger button 96 to be depressed to firethe instrument. As soon as roller 170 is released, spring 174 returnsthe safety mechanism to its normal position so as to prevent subsequentaccidental firings.

Turning to FIG. 15, the elongated portion 54 of surgical apparatus 50 isillustrated in exploded detail. At a proximal end of elongated portion54, piston 104 extends through clamp tube 70 (FIG. 12) and into theproximal end of a cover tube 182. Piston 104 is adapted for reciprocalmovement within clamp tube 70 in response to actuation of pneumaticsystem 68. The distal end of piston 104 is provided with an attachmentflange 184 for mounting a plurality of pusher washers 186 of the typewhich are well suited for high loads in small spaces. A spring supportwasher 188 is positioned on flange 184 for engaging the proximal ends ofinner and outer return springs 140 and 142. A lock washer 189 maintainsthe pusher washers 186 in a desired position on flange 184. Attachmentflange 184 has a chamfered distal tip and is configured and dimensionedto be received between the proximal opposed fingers 190 and 191 of achannel member 192.

As shown in FIG. 15, channel member 192 is defined by an elongatedstructure which is slidably mounted in elongated portion 54 forreciprocal longitudinal motion therein. As mentioned above, channel 192has opposed fingers 190 and 191 at a proximal end thereof to receiveattachment flange 184 of piston 104. A forked portion 194 is provided ata distal end portion of channel 192 defining a slot 196 therebetween.Forked portion 194 has a pair of opposed ramping surfaces 198 and 200,the function of which will be described in greater detail below.

An extension sleeve 204 is disposed within cover tube 182 and is fixedon a proximal end thereof to clamp tube 70. A sealing member 206 ismounted adjacent clamp tube 70 for sealably isolating frame portion 52of instrument 50 from elongated portion 54 thereof. Inner and outerreturn springs, 142 and 140 respectively, are contained within upperextension spacer 210 and lower extension spacer 212 which are, in turn,combined and fixed within the extension sleeve 204. Spring supportwasher 188 abuts the proximal ends of inner and outer return springs 142and 140 and, when instrument 50 is fired, transmits the energy of thecompressed springs 142 and 140 to the piston 104, returning it to itsprefired position.

A support structure 214 is also disposed within extension spacers 210and 212 adjacent the distal end thereof which functions to releasablyreceive cartridge assemblies in instrument 50. Support structure 214 isretained in place within combined extension spacers 210, 212 by atransverse support key 216. A clamp lockout structure is incorporatedinto support structure 214 and upper extension spacer 210. The clamplockout structure comprises a leaf spring 220 having a diagonallydownwardly extending projection 222 attached thereto. A slot 224 isformed through the top surface of support structure 214 and is adaptedto engage and receive projection 222 whenever the support structure isnot longitudinally aligned. This clamp lockout structure is designed andconfigured to prevent the instrument jaws from closing on tissue unlessthe cartridge and/or jaw elements are properly emplaced within theelongated portion 54 of apparatus 50.

Referring now to FIG. 16 and 17, anvil member 56 of surgical apparatus50 comprises an elongated distal body portion 230 and a proximalmounting shroud 232. Body portion 230 defines a staple forming plate 234(see FIG. 17) having a plurality of staple forming depressions 236provided therein into which staples are driven so as to be formed. Alongitudinal center groove 238 is also provided in staple forming plate234 to facilitate the guided passage of a surgical knife 240 during afiring sequence of apparatus 50. Mounting shroud portion 232 is definedby opposed side walls 242 and 244 which are dimensioned to fitcooperatively upon a portion of cartridge assembly 58. Apertures 246 areincluded in the opposed side walls 242 and 244 for mounting acylindrical pulley 248. Pulley 248 is maintained within shroud portion232 by opposed fastener ring pairs 250 and 252 and functions incooperation with a mechanism for moving anvil member 56 between an openposition and a closed position. A pair of opposed spaced apart arms 254and 256 extend longitudinally from the proximal end of shroud portion232 and have vertical mounting slots 258 and 260 provided therein,respectively, for receiving a mounting pin 262. Mounting slots 256 and258 enable anvil member 56 to adjust its position upon engaging tissueagainst forming plate 234. More particularly, slots 256 and 258 permitadjustment of the spacing between forming plate 234 and cartridgeassembly 58.

The articulating cartridge assembly 58 of the subject inventioncomprises a forward housing portion 270 and a rearward housing portion272. Forward housing 270 is defined by a channel structure ofsubstantially rectangular cross-section having opposed side walls 274and 276 and a bottom wall 278. This channel structure constitutes thecartridge receiving portion and is dimensioned to receive a cartridge280. A longitudinal groove structure 282 is defined in cartridge 280 forreceiving and guiding knife 240 therethrough. A plurality of stems 283extend downwardly from the undersurface of cartridge 280 for engagementin a plurality of corresponding apertures 287 formed in the bottom wall278 of forward housing 270. A plurality of pusher elements 284 aredisposed in cartridge 280 in abutment with a plurality of correspondingstaples 285. The staples 285 are advantageously arranged in sixlongitudinal rows with three rows positioned on either side of groovestructure 282. See, U.S. Pat. No.4,978,049 to Green, the disclosure ofwhich is incorporated herein by reference. In addition, two pairs oflongitudinal slots are formed in the cartridge housing 280 and areadapted to receive a pair of dual cam bars 286 and 288 therein. Cam bars286 and 288 each serve to drive three corresponding longitudinal rows ofstaples 285.

Cam bars 286 and 288 are each provided with a cam surface 290 in anupper distal end thereof and an overhanging ledge 292 with verticalsurface 294 in a lower distal end. This overhanging ledge 292 isdimensioned to extend into the longitudinal slots formed in cartridge280 to a point wherein the vertical surface 294 of overhanging ledge 292drops down and abuts the forward edge 296 of the forward housing portion270 cartridge assembly 58 when cam bars 286 and 288 move to their distalfired position. At their proximal ends, cam bars 286 and 288 areprovided with hook structure 298 for releasably engaging a cam baradapter 300.

Referring now to FIGS. 16, 19, and 23, one embodiment of cam bar adapter300 in accordance with the present invention is illustrated. Cam baradapter 300 comprises a forward section 302 and a rearward section 304.Forward section 302 is substantially rectangular in configuration andhas a central longitudinal groove 306 formed therein and dimensioned toreceive the longitudinal groove structure 282 on cartridge 280 when cambar adapter 300 is urged to its forwardmost position. Flanges 308 andshelves 310 function to removably retain the proximal ends of cam bars286 and 288. The rearward section 304 of cam bar adapter 300 isrectangular in configuration with projections 312 formed in the proximalend thereof. The rearward section is dimensioned to be receivable withinthe slot formed in forked portion 194 in channel member 192. Projections312 are dimensioned to engage ramping surface 198 so as to allow forkedportion 194 to ride up and over projections 312 when it is moved in thedistal direction. A vertical bore 314 and a longitudinal groove 316 areformed in the rearward section 304 of cam bar adapter 300 which retainand hold the shank portion 315 of knife 240.

Although cam bar adapter 300 is effective to maintain cam bars 286 and288 and to transport the same through cartridge assembly 58, it may bedesirable to provide a cam bar adapter which enables the proximal endsof cam bars 286 and 288 to move freely in a transverse direction whilebeing effectively maintained in a desired longitudinal position. Freemounting of the cam bars provides several advantages over fixed mountingwhich advantages will be discussed in detail hereinbelow. FIGS. 20-22illustrate this embodiment of the cam bar adapter and is designatedgenerally by reference numeral 320. Cam bar adapter 320 comprises a cambar support fixture 322 and a housing structure 324. Support fixture 322is defined by a substantially L-shaped structure having an elongated legportion 326 and a transverse leg portion 328. A slot 330 is provided inleg portion 326 for receiving the proximal end of dual cam bar 286 and asimilar slot 322 is provided in leg portion 328 for receiving theproximal end of dual cam bar 288. The staggered mounting of cam bars 286and 288 in L-shaped support structure 322 advantageously positions cambars 286 and 288 to more effectively eject the staples from cartridge285. Support fixture 322 is dimensioned so as to fit within arectangular channel 334 defined within housing structure 324. Channel334 accommodates support fixture 302 in such a manner so that it canmove freely therein.

The advantages of freely mounting cam bars 286 and 288 are bestexplained with reference to FIGS. 23 and 24. Cam bar adapter 300 isillustrated in FIG. 24, wherein the respective proximal portions of cambars 286 and 288 are fixedly mounted. Upon articulating the forwardhousing 270 of cartridge assembly 58, cam bars 286 and 288 arecompressed by opposed bearing members 340 and 342 disposed in forwardhousing 270. The compression of the cam bars 286 and 288 causes abuckling effect at the central spans thereof. The deflection isaccentuated because the proximal end portions of cam bars 286 and 288are fixed in cam bar adapter 300. In contrast, if cam bars 286 and 288are mounted in cam bar adapter 320 such that the respective proximal endportions thereof are maintained in the L-shaped support fixture 322which moves freely within channel 334 defined in housing structure 324,the degree of deflection or buckling across the central spans of cambars 286 and 288 is substantially decreased. By reducing the degree ofdeflection across the spans of cam bars 286 and 288, the amount of forceneeded to drive cam bars 286 and 288 is also decreased. Moreover, theamount of pressure required to be released by the pneumatic system fordriving cam bars 286 and 288 through a complete stroke will be less whenthe respective proximal end portions of cam bars 286 and 288 are mountedfreely rather than fixedly in a cam bar adapter.

The cam bars are often made of stainless steel, however, it has beenfound that forming the cam bars from a shape memory alloy comprising,for example, a composition of nickel and titanium (such a composition isavailable from Raythem Corp., Menlo Park, Calif. under the trade nameTINEL), rather than stainless steel, will reduce the amount of forcerequired to drive cam bars 286 and 288 through a firing sequence.

Referring to FIGS. 18, 19, 23, and 24, bearings 340 and 342 are mountedin a pair of opposed ports 344 and 346 provided in the opposed sidewalls 274 and 276 respectively, adjacent the proximal end of forwardhousing 270. Bearing members 340 and 342 have a truncated triangularconfiguration defining a planar bearing surface for guiding cam bars 286and 288 as they traverse cartridge assembly 58 at such times when it isin an articulated position and, in addition, compress the cam bars asthey travel into cartridge 280 as discussed above.

Referring again to FIGS. 20-22, housing structure 324 of cam bar adapter320 is further provided with a pair of spaced apart apertures 350 and352 for retaining a pair of corresponding prongs 354 and 356 formed onthe shank 358 of knife 240. The rearward section 360 of housingstructure 324 is of rectangular configuration and defines a structurefor engaging groove 196 in channel member 192. Seats 362 and 364 areprovided on either side of rearward section 360 for engaging the forkedportion 194 of channel member 192.

Referring again to FIGS. 16, 18 and 19, a flange 366 extends outwardlyfrom the proximal end of the bottom wall 278 of forward housing 270 andincludes an aperture 368 for receiving a rivet 370. Rivet 370 alsoextends through an aperture 372 provide in a flange 374 which extendsoutwardly from the distal end of rearward housing 272. This rivetconnection enables forward housing 270 to articulate relative torearward housing 272.

Rearward housing 272 is defined by a channel of U-shaped cross-sectionhaving opposed side walls 376 and 378 and a bottom wall 380. Lockingslots 382 and 384 are formed in the opposed side walls 376 and 378adjacent the proximal end thereof for engaging and retaining supportstructure 214 (see FIG. 15). A pair of opposed crimps 386 and 388 areprovided in opposed side walls 376 and 378 adjacent locking slots 382and 384 for establishing a friction fit with cam bar adapter 300 (or inthe alternative cam bar adapter 320) within which the dual cam bars 286and 288 are mounted.

Referring now to FIGS. 15, 16, and 28, the movement of anvil member 56relative to cartridge assembly 58 in this embodiment is achieved througha linkage and cable system. This system includes a tube collar 400 whichmounts on the distal end of combined upper and lower extension spacers210, 212. Tube collar 400 has an internal partition wall 402 formedtherein through which extends an aperture having a diameter whichpermits the passage of a cable 404 therethrough, while prohibiting thepassage of an anchor ball 406 which is fastened to the trailing end ofcable 404. As it extends from partition wall 402, the line of action ofcable 404 is reversed from a proximal direction to a distal direction byturning about a pulley assembly which includes an annular pulley 410mounted on a pulley shaft 412, and retained thereon by a locking ring414. Pulley shaft 412 is supported in an aperture 416 provided adjacentthe proximal end of support structure 214. Upon turning about pulley410, cable 404 extends back through tube collar 400, avoiding partitionwall 402 and thereafter extending through a mounting collar 418positioned on the distal end of outer cover tube 182 of elongatedportion 54. Cable 404 then extends through a longitudinal bore hole 420formed in a pivot block 422. Pivot block 422 is rotatably mounted on aflange 424 extending from mounting collar 418 by a threaded fastener 426maintained in threaded aperture 425. Threaded fastener 426 extendsthrough an aperture 428 which is provided in flange 424. The functionand structure of pivot block 422 will be discussed in greater detailbelow with respect to the mechanism for articulating cartridge assembly58. After passing through bore hole 420 in pivot block 422, cable 404turns about cylindrical pulley 248 which translates the line of actionof cable 404 in a direction perpendicular to the longitudinal axis ofelongated portion 54. The cable 404 is terminated at the trailing endthereof at an upper face of a cable separation block 424. A U-shapedanchor cable 427 extends from the opposed face of cable separator block424 and is dimensioned and configured to engage the forward housing 270of articulating cartridge assembly 58 so as to anchor the cablemechanism. Preferably, a cover tube, which may be formed of aluminum ora like material, clothes anchor cable 427.

The position of cable separator block 424 with respect to cylindricalpulley 248 can vary. For example, cable separator block 424 can bedisposed proximal to pulley 248 as illustrated in FIG. 36. In thisinstance, the cylindrical pulley 248 would be configured with a pair ofspaced apart annular grooves or tracks for accommodating the U-shapedanchor cable 427.

During operation of apparatus 50, reciprocating movement of the combinedextension spacer 210, 212 in response to articulation of handle member62 in frame portion 52, will cause corresponding translation of tubecollar 400, thereby causing cable 404 to move in a longitudinaldirection about annular pulley 410, and subsequently about cylindricalpulley 248 in a perpendicular direction. As the trailing end of cable404 moves about pulley 248, it exerts a force thereupon whichconsequently causes anvil member 56 to move relative to the cartridgeassembly 58.

Apparatus 50 further comprises a mechanism for effectuating thearticulation of the forward housing 270 relative to the rearward housing272 of cartridge assembly 58. The articulation mechanism includes, asstated previously, pivot block 422. As best seen in FIGS. 25-27, pivotblock 422 comprises a substantially rectangular body portion 430 throughwhich extends longitudinal bore hole 420, and a transverse bore hole 432for receiving pivot pin 262 about which anvil member 56 pivots when thecable and linkage system is employed as described hereinabove. Alongitudinal groove 434 is provided in the undersurface of body portion430 for permitting passage of knife 240 as it traverses cartridgeassembly 58 mounted upon cam bar adapter 300. A fixed capstan 436comprising a shaft portion 438 and a hood portion 440 extends upwardlyfrom the body portion 430 of pivot block 422 about which an articulationcable 442 of looped configuration is supported. More particularly, cable442 has an anchor ball 444 intermediate its length which is dimensionedand configured to be fixed within a port 446 formed in shaft portion 438of capstan 436 (see FIG. 26.).

As best seen in FIG. 27, the walls of longitudinal bore hole 420 diverge45° from the central axis thereof at a central point within body portion432 so as to define a mouth 448 at the proximal face 450 of pivot block422. The diverging mouth 448 of longitudinal bore hole 420 enables therelative movement of cable 404 during articulating movement of cartridgeassembly 58 within a 90° sector of translation wherein θ_(A) and θ_(B)and each equal to 45°. It is also envisioned that, where a wider sectionof translation is desired, pivot block 422 and any associated structuralelements of the apparatus may be modified to achieve at least 60° ofarticulation in either direction relative to the longitudinal axis ofthe instrument. The section of articulation cable 442 opposite anchorball 444 is connected to a dial member 452 which is provided in theelongated portion 54 adjacent the proximal end thereof. Rotation of dialmember 452 in either the clockwise or counter clockwise direction (seeFIGS. 31 and 32, respectively) will cause articulating cable 442 totranslate in such a manner so as to cause pivot block 422 to rotate onan axis perpendicular to the longitudinal axis of elongated portion 54about threaded fastener 426. Consequently, anvil member 56, which isconnected to pivot block 422 through pin member 262, and forward housing270 which is operatively associated with anvil member 56 throughU-shaped anchor cable 427, is caused to pivot about rivet member 370.

In use, the elongated portion 54 of instrument 50 is inserted into thebody, preferably through an endoscopic tube. It is further preferredthat the endoscopic tube apparatus be capable of maintaining a sealedpneumoperitoneum, with the internal sealing member of the housingfurther maintaining this seal despite introduction of the instrument inaccordance with the invention into the endoscopic tube. As a practicalmatter, the jaws of the instrument are closed for insertion into theendoscopic tube, either by pinching the anvil and cartridge prior toinsertion or by closing the articulating handle to cam the jaws closedprior to insertion.

Referring to FIGS. 29 and 30, with the instrument properly oriented sothat the tissue to be fastened is disposed between the open jaws of theinstrument, i.e., between the tissue contacting surfaces of anvil member56 and cartridge 280, the jaws are closed to clamp the tissue. Closureof the jaws is achieved as the surgeon presses down on articulatinghandle member 62, so as to slide tube collar 400 distally, via clamptube 70, extension sleeve 204, and extension spacers 210, 212.

The leading end of cable 404 is drawn in a distal direction as anchorball 406 is maintained against partition wall 402. As the leading end ofcable 404 is drawn distally, the intermediate section thereof which isturned about annular pulley 410 is drawn in a proximal direction.Consequently, the trailing end of cable 404 is urged in an upwarddirection, perpendicular to the longitudinal axis of elongated portion54, as it turns about cylindrical pulley 248, thereby exerting adownward force upon pulley 248 and urging anvil member 56 to approximatetoward the tissue engaging surface of cartridge assembly 58.

Where articulation is necessary or desired to orient the jaws prior toclamping, the forward housing 270 of cartridge assembly 58 may bearticulated relative to the elongated portion 54 of apparatus 50 withina 90° sector of rotation, and in particular within a 45° sector ofrotation on either side of the longitudinal axis of the elongatedportion 54 of apparatus 50. Referring to FIG. 31, clockwise rotation ofdial member 452 will result in clockwise articulation of forward housing270 and anvil member 58. In particular, as dial member 452 is rotated,the lateral portions of articulation cable loop 426 translate inopposite longitudinal directions causing anchor ball 444 mounted in theshaft portion 438 of fixed capstan 436 of pivot block 422 to urge pivotblock 422 in such a manner so as to rotate in a clockwise directionabout threaded fastener 426. At such a time, the forward housing 270pivots about rivet 370 relative to the rearward mounting portion 272 ofcartridge assembly 58. Similarly, rotation of dial member 452 in acounter-clockwise direction as shown in FIG. 32, will articulatecartridge assembly.

After closing the instrument jaws, the instrument is ready to be fired.When the surgeon is ready to emplace the staples and cut tissue, firingtrigger 96 is depressed to actuate the pneumatic actuator 92 asdiscussed in detail above. Piston 104, attached to the proximal end ofchannel 192 is driven distally causing the camming surface of forkedportion 194 to ride up and over projection 362 of the cam bar adapter300 and drive the cam bar adapter in a distal direction. Thereupon, thecam bars 286 and 288 and knife 240 are driven longitudinally through thecartridge to sequentially drive and form staples.

As piston 104 cortacts return springs 140, 142, pusher washers 186 arecompressed on themselves and serve to store energy as the piston movesdistally toward the cartridge assembly. This initial compression occursin the range of between about 20 p.s.i. to about 150 p.s.i. andpreferably within a range of about 30 p.s.i. to about 60 p.s.i. Near theend of the distal stroke of the piston 104, this stored energy isreleased to drive the cam bars 286 and 288 through the final distallimits of their travel within the longitudinal slots in the cartridge250. At the distal extreme of the longitudinal stroke, the overhangingledges 292 of cam bars 286 and 288 drop over the edge of the forwardcartridge housing 270 thus abutting vertical surface thereof.

Referring to FIGS. 33 and 35, after firing, return springs 140, 142engage piston 104 and return it to its original position. The returnmotion of piston 104 causes rocking lever 120 to be cammed aside bycamming surface 144 of piston 104. Subsequently, the L-shaped supportfixture and cam bars 286 and 288 are pulled out of cam bar adapter 320and remain in position in the longitudinal slots of the cartridge 280.The cam bar adapter 320, with knife 240 attached, moves proximallywithin rearward cartridge mounting portion 272 until the outer edges ofcam bar adapter 320 impinge on crimps 296.

The cam bar adapter 320 is held in place by crimps 296 while cammingsurfaces 198 and 200 of forked portion 194 causes the fork to ride upand disengage with projections 312 of the cam bar adapter 300. Channelmember 192 continues to move in the proximal direction until it reachesits rest position. At this point, the entire cartridge assembly 158 isdeactivated.

In the event that the surgeon should accidentally attempt to again firethe instrument without replacing the deactivated cartridge with a newunfired cartridge, the resulting distal longitudinal motion of thechannel 192 moves abutting structure 202 into contact with rearwardprojection 290 effectively preventing further movement of forked portion194 toward cam bar adapter 280.

After firing, articulating handle 62 is raised with the assistance ofhandle return spring 82 which action retracts collar tube 400. Thisretraction causes anvil 56 to move of engagement with cartridge assembly158. Similarly, raising of articulating handle 62 causes cam slide 124to move upward disengaging the pneumatic firing mechanism.

In order to replace the articulating cartridge assembly 58, theinstrument is withdrawn from the patient. Thereafter, the cartridgeassembly is removed from the elongated portion 54 of apparatus 150. Toreinsert a new cartridge assembly, the proximal mounting portion 272 ofcartridge assembly 158 is inserted into the distal end of elongatedportion 154. The instrument is now ready for reinsertion and continueduse.

Turning now to FIGS. 36 and 38, another preferred embodiment of thesurgical apparatus of the subject invention is illustrated and isdesignated generally by reference numeral 500. Surgical apparatus 500functions in much the same manner as the surgical instrument 50previously described, with the exception of the mechanism foreffectuating the articulation of the cartridge assembly 58.Specifically, the articulation mechanism of surgical apparatus 500comprises two assemblies, including a parallel crank linkage assembly505 disposed adjacent the cartridge assembly 58 at the distal end ofelongated portion 54, and an actuation assembly, shown generally at 510,located adjacent the frame portion 52 of the apparatus at the proximalend of elongated portion 54. In the discussion which follows, both thelinkage assembly 505 and the axial barrel cam assembly 510 will bedescribed with respect to various embodiments. It will be appreciatedhowever, by those having ordinary skill in the art, that any of theassemblies described herein may be modified to incorporate featuresshown in the various preferred embodiments.

Turning to FIGS. 40-42, the parallel crank linkage assembly 505 ofsurgical apparatus 500 is associated with a mounting collar 512 havingan engaging portion 514 adapted for mounting within the distal end ofcover tube 182. The linkage assembly 505 includes a proximal crankmember 516 mounted for rotation about a pivot pin 518 which extendsthrough the rearward flange portion 520 of mounting collar 512. Pivotpin 518 is disposed perpendicular to the longitudinal axis of elongatedportion 54. Longitudinally spaced from proximal crank member 516, adistal crank member 522 is mounted for rotation about a pivot pin 524.Pivot pin 524 extends through the forward flange portion 526 of mountingcollar 512 and is disposed parallel to pivot pin 518. Distal crank 522is associated with a pivot block 528 having a longitudinal bore 530extending therethrough for accommodating cable 404. As previouslydescribed herein, cable 404 is associated with moving anvil member 56between an open position and a closed position for clamping tissue.Pivot block 528 is also provided with a transverse bore 532 foraccommodating the transverse pin 262 about which anvil member 56 pivotsas it is moved between its open and closed positions.

Linkage assembly 505 further comprises a pair of parallel coupler links534 and 536 which operatively interconnect the proximal crank member 516and distal crank member 522. Link 534 has a longitudinal span 538 with atransverse engaging slot 540 formed at a distal end thereof for engaginga pin 542 associated with distal crank 522, and a transverse engagingslot 544 is provided at the proximal end thereof for engaging anotherpin 546 associated with the proximal crank 516. Similarly, link 536 hasa longitudinal span 548 with a transverse engaging slot 550 provided atthe distal end thereof for engaging a pin 552 associated with the distalcrank member 522, and a transverse slot 554 is formed at the proximalend thereof for engaging yet another pin 556 disposed on the proximalcrank member 516. Of the two coupler links 534 and 536, link 534 definesa driver link, while link 536 defines a follower link. Moreover, driverlink 536 is provided with a coupling 558, which decends from theundersurface thereof, intermediate span 538 for receiving and mountingthe distal end of an elongated transmission rod 560. Transmission rod560 extends through the elongated portion 54 of surgical apparatus 500for transmitting reciprocal longitudinal motion to driver link 534 inresponse to manipulation of the axial barrel cam assembly 510.Transverse slots 540, 544, 550, and 554 permit coupler links 534 and 536to remain parallel to a longitudinal axis of the linkage assembly 505during transmission of the reciprocal longitudinal motion by rod 560.

Referring again to FIGS. 36-39, the actuation assembly 510 of surgicalapparatus 500 comprises a generally cylindrical manipulator sleeve 562disposed about the proximal section of elongated portion 54. Manipulatorsleeve 562 is configured and dimensioned for axial movement with respectto the longitudinal axis of elongated portion 54. In particular,manipulator sleeve 562 may be rotated about the longitudinal axis ofelongated portion 54 to rotate the cartridge assembly 58 relative to theframe portion 52 of apparatus 500, and reciprocally in a generallylongitudinal direction for effectuating the articulation of cartridgeassembly 58 so as to increase the range of operability of theinstrument, which will be described in greater detail hereinbelow.

A barrel cam 564 having a substantially hemi-cylindrical configurationis associated with manipulator sleeve 562 and is configured anddimensioned for rotational movement as sleeve 562 is manipulated in alongitudinal direction to drive transmission rod 560. Relativerotational movement of barrel cam 564 is facilitated by the interactionof a cam follower pin 566 extending radially inward from manipulatorsleeve 562, and a cam slot 568 defined in barrel cam 564. Cam slot 568has a three stage configuration including an upper step region 570, acentral step region 572, and a lower step region 574. When articulatingthe cartridge assembly 58 of surgical apparatus 500 in acounter-clockwise direction, sleeve 562 is manipulated in a proximaldirection, moving cam follower pin 566 from the central step region 572,wherein cartridge assembly 58 is in substantial longitudinal alignmentwith the elongated portion 54 of the instrument, to the upper stepregion 570 of cam slot 568, to axially rotate barrel cam 564.

To articulate cartridge assembly 58 in clockwise direction, sleeve 562is manipulated in a distal direction, moving cam follower pin 566 to thelower step region 574 of cam slot 568, and thereby axially rotatingbarrel cam 564. The longitudinal dimension of cam slot 568 can bemodified depending upon the tactile sensation desired to be transmittedto the user of the instrument. In addition, an annular rib 563 (see FIG.38) extending radially outward from the cover tube 182 of elongatedportion 54, distal to manipulator sleeve 562, serves to preventover-insertion of the elongated portion 54 of surgical apparatus 500into a trocar or cannula device.

As stated briefly above, the rotational movement of barrel cam 564 isconveyed to transmission rod 560 for effectuating the articulation ofcartridge assembly 58. This conveyance of rotational motion isaccomplished by engaging an arm 580 formed at the proximal end oftransmission rod 560 within an angled drive slot 582 defined in barrelcam 564. Thus, as barrel cam 564 rotates in response to the translationof cam follower pin 566 within cam slot 568, transmission rod 560 isadvantageously driven in a longitudinal direction as the peripheralwalls of angled drive slot 582 are urged against the engaging arm 580thereof. To secure the engagement of arm 580 within angled drive slot582, a connective fitting 584 is mounted atop engagement arm 576 and isconfigured and dimensioned to move within longitudinal channel 585formed in an inner surface of manipulation sleeve 562.

Barrel cam 564 is also provided with a pair of spaced apart transversealignment slots 586 and 588 which are adapted and configured forcooperatively receiving a pair of guide pins 590 and 592. Guide pins 590and 592 are associated with the outer tube 182 of elongated portion 54and inhibit undesirable longitudinal shifting of the barrel cam 564which may arise as sleeve 562 is manipulated. In addition, guide pins590 and 592 achieve connection between the outer tube 182 of elongatedportion 54 and the manipulator sleeve 662 via the interaction of camfollower pin 566 and cam slot 568. This connection is further assistedby the provision of a spring loaded locking mechanism associated withmanipulator sleeve 562.

As best seen in FIGS. 37 and 39, the locking mechanism includes a lockball 594 which is biased by a coiled spring 596 maintained within acavity 598 formed within manipulator sleeve 562. Lock ball 594 isselectively engageable within a plurality of spaced apart notchesdisposed about the outer circumference of cover tube 182 and including aprimary notch 600 corresponding to the cam follower pin 566 beingdisposed in the upper step region 570 of cam slot 568, a secondary notch602 corresponding to cam follower pin 566 being disposed in the centralstep region 572 of cam slot 568, and a tertiary notch 603 correspondingto cam follower pin 566 being disposed in the lower step region 574 ofcam slot 568. By lockingly engaging the cover tube 182 of elongatedportion 54, rotation of manipulator sleeve 562 about the longitudinalaxis of elongated portion 54 will effectuate remote rotation ofcartridge assembly 58 relative to the frame portion 52 of surgicalapparatus 500.

In use, as sleeve 562 is manipulated in a distal direction (see FIG.38), transmission rod 560 will translate in a proximal direction withrespect to elongated portion 54, pulling driver link 534 proximally asindicated by arrow "A" in FIG. 43. In response, distal crank member 522is rotated about pivot pin 524, thereby turning pivot block 528 in aclockwise direction. As pivot block 528 is operatively connected toanvil member 56 through transverse pin 262, the forward housing 270 ofcartridge assembly 58 is caused to articulate in a clockwise direction.Similarly, in response to manipulation of sleeve 562 in a proximaldirection (see FIG. 36), transmission rod 560 will translate distallywith respect to elongated portion 54, pushing driver link 534 distallyas indicated by arrow "B" in FIG. 44. As a result, distal crank member522 will turn pivot block 528 in a counter-clockwise direction,articulating the forward housing 270 of cartridge assembly 58 in acounter-clockwise direction.

Another preferred embodiment of the parallel linkage assembly 505 of themechanism for effectuating the articulation of cartridge assembly 58 isillustrated in FIGS. 45-49. This assembly includes a looped cable 620,which replaces the parallel coupler links 534 and 536 discussedhereinabove, for operatively associating the spaced apart proximal anddistal crank members 516 and 522, which, in this embodiment, serveprimarily as a pair of capstans. A first ball-type fastener 622 isprovided at the leading portion of cable loop 620 for securing the cableto distal crank member 522, and a second ball-type fastener 624 isprovided at the trailing portion of cable loop 620 for fixing the cableto proximal crank member 516. A coupling 626 is rigidly mounted on thedriving leg 628 of cable loop 620 for operatively receiving andretaining the distal end of transmission rod 560 so as to interconnectthe actuation assembly 510 of surgical apparatus 500 to the linkageassembly 505 thereof.

Referring to FIG. 47, in use, the cable loop 620 is manipulated throughlongitudinal translation of transmission rod 560 in response tomanipulation of barrel cam assembly 510 (see FIGS. 36 and 38). Thus,proximal translation of transmission rod 560, as indicated by arrow "C"in FIG. 48, will cause cable loop 620 to rotate in a clockwisedirection, turning pivot block 528 in a clockwise direction toarticulate the forward housing 270 of cartridge housing 58 through anarcuate path (see FIG. 38). Similarly, distal translation oftransmission rod 560, as indicated by arrow "D" in FIG. 49, will causecable loop 620 to rotate in a counter-clockwise direction, causingdistal crank member 522 to pivot in a counter-clockwise direction. As aresult, the forward housing 270 of cartridge assembly 58 will be movedarcuately in a counter-clockwise direction (see FIG. 36).

Another preferred embodiment of the actuation assembly 510 isillustrated in FIGS. 50 and 51, and is particularly adapted andconfigured for progressively articulating cartridge assembly 58 withinan angular sector of rotation. This assembly comprises a sleeve member650 disposed about the elongated portion 54 of surgical apparatus 500adjacent the frame portion 52 thereof. A continuous helical track 652 isdefined about the outer circumference of the distal end portion 654 ofsleeve member 650, and a knurl 656 is formed at the proximal end portionof sleeve member 650. An annular knob member 658 is mounted coaxial withthe distal end portion of sleeve member 650 and is provided with a pairof opposed and staggered follower pins 660 and 662 which are configuredand positioned to travel within helical track 652 as knob member 658 isrotated relative to sleeve member 650 for effecting the progressivearticulation of cartridge assembly 58.

A retainer ring 664 having an annular flange portion 668 is mountedwithin an annular groove 670 defined in knob member 658. Retainer ring664 is also provided with an engagement port 672 for receiving theengaging arm 580 formed at the proximal end of transmission rod 560. Apair of diametrically opposed grooves 674 and 676 are formed in theinterior of retainer ring 664 for engaging a pair of opposedcorresponding keys 678 and 680 which extend radially outward from thecover tube 182 of elongated portion 54 adjacent sleeve member 650.Through this engagement, rotation of transmission rod 560 will beinhibited as knob member 658 is rotated to drive transmission rod 560 ina longitudinal direction for effectuating the progressive articulationof cartridge assembly 58. However, when sleeve member 650 is rotatedabout the longitudinal axis of elongated portion 54, the engagement ofthe keys 678 and 680 within the opposed grooves 674 and 676 willeffectuate rotation of cartridge assembly 58 relative to the frameportion 52 of surgical apparatus 500. Finally, a securement ring 682 isfastened to the distal face 684 of knob member 658 by a plurality ofthreaded fasteners 686 for maintaining retainer ring 664 within annulargroove 670.

Referring to FIG. 52, another preferred embodiment of a surgicalinstrument in accordance with the subject invention is illustrated andis designated generally by reference numeral 700. This instrument isintended to provide the surgeon with a substantially increased range ofoperability during a surgical procedure. In brief, surgical instrument700 comprises a frame or handle assembly 702, an elongated body portion704 extending from the handle assembly 702 and defining a longitudinalaxis, and a fastener applying assembly 706 which is pivotably associatedwith a distal end 708 of body portion 704.

The fastener applying assembly 706 includes a base portion 710 which ispivotably mounted to the distal end 708 of body portion 706 by means ofa main joint pin 707 (see generally FIG. 63). A cartridge assembly 712is configured to be mounted within the base portion 710 and an anvilmember 715 is positioned adjacent the cartridge assembly 712 againstwhich staples ejected from the cartridge assembly are formed (seegenerally FIG. 58).

Surgical instrument 700 includes three mechanisms for effectuatingdistinct movements of the fastener applying assembly 706. Thesemechanisms include a rotation control mechanism for effectuatingrotation of the fastener applying assembly 706 about a longitudinal axisdefined by the elongated body portion 704. This first mechanism isoperated through rotation of a control knob 714 which is fixed about theproximal end of body portion 704 (see FIG. 52). The second mechanism isan articulation control mechanism for moving the base portion 710 of thefastener applying assembly 706 relative to the elongated body portion704 within an angular sector of rotation. This second mechanism isoperated through rotation of control knob 716 (see FIG. 53). A thirdmechanism is provided for controlling the independent rotation of thecartridge assembly 712 together with the anvil member 715 relative tothe base portion 710 of the fastener applying assembly 706 (see FIG.54). This third mechanism is operated through rotation of control knob718. These control mechanisms will be described in greater detailhereinbelow.

Referring now to FIGS. 55-57, the handle assembly 702 of surgicalinstrument 700 includes a handle body 720 for enclosing a pneumaticactuation which is operative to effectuate the ejection of surgicalstaples from the cartridge assembly 712. This pneumatic assembly issimilar in many respects to those described hereinabove. However, thepneumatic assembly of FIGS. 55-57 serves to create a power stroke whichis directed in a proximal direction rather than a distal direction. Inbrief, the pneumatic assembly includes a gas supply container 722, apiston member 724 having a piston head 727 accommodated within acylinder 725 and a coiled return spring 726. As best seen in FIG. 57,piston head 727 has a substantially elliptical configuration, as doesthe cylinder 725 within which it is accommodated. The ellipticalconfiguration of piston head 727 and cylinder 725 provides increasedpower during a staple driving operation while maintaining substantiallythe same overall dimensions of the handle assembly 702. In a preferredembodiment of the invention wherein surgical instrument 700 is adaptedto apply six rows of staples, each staple row measuring about 60 mm inlength, and to simultaneously cut between the two innermost staple rows,the major axis of elliptical piston head 727 is between about 0.65 and0.70 inches, and the minor axis is between about 0.45 and 0.50inches.The corresponding elliptical cylinder 725 has a major axis of about 0.80to 0.85inches and a minor axis of about 0.60 to 0.65 inches. Anelliptical O-ring is provided on piston head 727 to pneumatically sealpiston head 727 to cylinder 725. Other cross-sectional configurationsare also contemplated and are within the scope of the invention. Aflexible conduit 723 connects the gas supply container 722 to piston 724for the delivery of compressed gas. In use, the delivery of compressedgas from the container 722 is controlled by a trigger 731 disposed atthe proximal end of handle body 720. Operation of trigger 731 to firethe instrument is substantially identical to that described above withrespect to the other embodiments of the invention.

An elongated actuation rod 728 is associated with piston 724 and extendsoperatively therefrom, through the body portion 704 of surgicalinstrument 700, to the distal end 708 thereof. The distal end ofactuation rod 728 is mounted to a cartridge adapter 730 which isillustrated in FIG. 62 in conjunction with the removable cartridgeassembly 712. Adapter 730 interconnects actuation rod 728 to a steppeddraw bar 732. Draw bar 732 defines a proximal section 734, anintermediate stepped section 736, and a distal section 738. The distalsection 738 of draw bar 732 extends through the cartridge assembly 712,beneath the staple carrying cartridge 737 disposed therein, to connectwith a staple ejecting assembly associated with the cartridge assembly712.

Referring to FIGS. 58 and 59, the staple ejecting assembly includes acam driver 740 which serves to drive a plurality of spaced apart cammembers, i.e. cam members 742. The cam members are disposed within, andtranslate along, a plurality of tracks defined in the staple containingcartridge 737 (see generally FIG. 18). Cam members 742 are dimensionedand configured to effect the sequential ejection of a plurality ofsurgical staples from the staple containing cartridge 737 as a result oftheir travel from an initial distal position to a final proximalposition. The staple ejecting assembly further comprises a knife blade744 mounted upon a shank 746 which is adapted to translate with andbehind cam members 742 during a stapling operation to divide the stapledtissue. The ejection of staples from the cartridge is accomplished muchin the same way as that which has been described hereinabove withrespect to previous embodiments of the subject invention. However, asdescribed herein, cam members 742 translate from a distal to a proximaldirection to sequentially drive the staples from the cartridge.

In operation, the sequential ejection of a plurality of surgical staplesfrom the staple containing cartridge 737 is effectuated by depressingtrigger 731. Movement of trigger 731 will cause gas to be released fromsupply container 722 which will exert pressure upon the ellipticalpiston head 727, urging piston 724 in a proximal direction. As piston724 translates proximally, return spring 726 is compressed, andactuation rod 728 is drawn proximally therewith. As a result, draw bar732 is pulled proximally within the elongated portion 704 of surgicalinstrument 700. The proximal translation of draw bar 732 causes the cammembers 742 to travel in proximal direction within the tracks which aredefined in the staple containing cartridge 737. Once the cam bars havecompleted their proximal-to-distal translation through thestaple-containing cartridge 737, the pressurized cylinder 725 ventsthrough a plurality of circumferentially disposed apertures 747, therebypermitting compressed return spring 726 to drive piston 724 distallyinto its initial pre-fired position. The distal movement of actuationrod 728 in response to decompression of return spring 726 causescartridge adaptor 730 to return cam members 732 distally throughstaple-containing cartridge 737. However, knife blade 744 preferablyremains in its proximal-most position by disengaging from the staplefiring mechanism, e.g., by becoming lodged in a plastic knife block atthe proximal end of the knife blade's travel path throughstaple-containing cartridge 737.

Referring to FIGS. 55 and 56, handle assembly 702 further comprises anactuation lever 750 for controlling the approximation of the cartridgeassembly 712 and the anvil member 715. Actuation lever 750 isoperatively connected to an approximation cable 754 which extendsthrough the body portion 704 of surgical instrument 700 to anapproximation link 755 associated with the fastener applying assembly706. The distal end 756 of cable 754 is terminated in a universal balljoint fitting 758 which is maintained within a cavity 760 defined withinapproximation link 755. The entryway to cavity 760 is tapered toaccommodate the angular bending of cable 754 during approximation.

Approximation link 755 is normally biased into the position shown inFIG. 58 so as to maintain the cartridge assembly 712 and anvil member715 in an open position. This may be accomplished by known biasingstructure including, for example, a leaf, compression or torsion spring.Approximation link 755 is pivotably associated with cartridge assembly712 through a transverse pivot pin 762, and it is associated with theanvil member 715 through a cam pin 764. Cam pin 764 is dimensioned andconfigured to cooperate with a cam slot 766 which is defined withinarticulator link 755. To approximate the cartridge housing 712 towardthe anvil member 715 to engage tissue therebetween, lever 750 is movedfrom the position shown in FIG. 55 to that of FIG. 56, causingapproximation cable 752 to be drawn proximally. As approximation cable752 is drawn proximally, link 755 will rotate about pivot pin 762 in aclockwise direction, urging cam pin 764 to move through an arcuate pathunder the influence of cam slot 766, thereby approximating cartridgeassembly 712 and anvil member 715.

Turning now to FIGS. 61 and 63, in conjunction with FIG. 53, themechanism for effectuating the articulated movement of the fastenerapplying assembly 706 relative to the elongated portion 704 of surgicalinstrument 700 includes a planetary gear assembly 770. Planetary gearassembly 770 is operatively connected to the base portion 710 offastener applying assembly 706 by means of an offset elongatedtransmission link 772 which extends through body portion 704. Asillustrated in FIG. 61, the planetary gear assembly 770 is associatedwith knob 716 and includes an outer ring gear 774, an internal gear 776which rotates about a fixed axis in response to the rotation of outerring gear 774, and a worm gear 778. Worm gear 778 extends through thecenter of the internal gear 776 and translates longitudinally inresponse to rotation of internal gear 776. Worm gear 778 is operativelyconnected to the proximal end of the elongated transmission link 772.The distal end of transmission link 772 is pivotably connected to thebase portion 710 of fastener applying assembly 706 by means of pivot pin780. Thus, in operation, rotation of knob 716 in the direction indicatedby arrow "A" in FIG. 53 will cause corresponding longitudinaltranslation of offset link 722, articulating the fastener applyingassembly 706 within an angular sector of rotation, i.e. within a 45°sector of rotation with respect to the longitudinal axis defined by theelongated body 704 as indicated by arrow "A'" in FIG. 53 to increase therange of operability of the apparatus of the subject invention. Althoughthe surgical instrument 700 is shown with a base portion articulatablein only a singular radial direction, it is well within the scope of thepresent invention to provide for a base portion capable of articulationin symmetric radial directions as shown in the preceding embodiments.

Referring now to FIGS. 60, 63, and 64, in conjunction with FIG. 54, themechanism for effectuating the independent rotation of the cartridgeassembly 712 together with the anvil member 715 relative to the baseportion 710 of the fastener applying assembly 706 includes proximal anddistal planetary gear assemblies 782 and 784. The proximal planetarygear assembly 782 is interconnected to the distal planetary gearassembly 784 by means of an offset elongated transmission axle 786.Proximal planetary gear assembly 782 is associated with the distalmostcontrol knob 718 on elongated body portion 704 and is illustrated inFIG. 60. Gear assembly 782 includes an outer ring gear 788 which rotatesin response to rotation of knob 718, and an internal gear 790 which isconfigured to rotate about a fixed axis in response to the rotation ofouter ring gear 788. The proximal end of transmission axle 786, whichpreferably has a hexagonal cross-section, is axially mounted within theinternal gear 790 and is configured to rotate therewith in response torotation of knob 718.

The distal planetary gear assembly 784, which is illustrated in FIG. 64,is associated with the base portion 710 of fastener applying assembly706 and includes an outer pinion gear 792. Pinion gear 792 is configuredto rotate in response to the rotation of transmission axle 786. Moreparticularly, the outer pinion gear 792 is mounted to transmission axial786 by means of a flexible coupling rod 794 which may be fabricated froma pseudoelastic material such as, for example, TINEL material. Othertypes of rotational drive structure are also contemplated and are withinthe scope of the invention. These include, for example, universaljoints, reinforced flex cabling, etc. The proximal end of coupling rod794 is mounted in the distal end of the transmission axle 786, and thedistal end thereof is mounted to a fitting 796 which is operativelyassociated with outer pinion gear 792. The distal planetary gearassembly 784 further includes an internal ring gear 798 which isconfigured to rotate in response to the rotation of pinion gear 792.

As best seen in FIG. 63, the proximal end of the cartridge assembly 712defines an adapter fitting 800, which is dimensioned and configured tomount operatively within the internal ring gear 798 of the distalplanetary gear assembly 784 so as to effectuate the independent rotationthereof relative to the base portion 710 of fastener applying assembly706. Thus, in operation, rotation of the distal knob 718 in thedirection indicated by arrow "B" in FIG. 54 will cause correspondingrotation of transmission axial 786, which, in turn, will rotate theflexible coupling rod 794. In response, the outer pinion gear 792 willrotate, causing the internal ring gear 798 to rotate along withcartridge assembly 712 in the direction indicated by arrow "B'" in FIG.54. Furthermore, since the anvil 715 is mounted adjacent the cartridgehousing 712 it will rotate therewith so as to further increase the rangeof operability of the surgical apparatus of the subject invention.

It will be understood by those having ordinary skill in the art thatvarious modifications or changes can be made to the various embodimentsof the subject invention herein disclosed without departing from thespirit or scope thereof. For example, various sizes of the instrumentare contemplated, as are various types of construction materials.Therefore, the above description should not be construed as limiting theinvention, but merely as exemplifications of preferred embodimentsthereof.

To the extent not already indicated, it will also be understood by thosehaving ordinary skill in the art that any one of the specificembodiments herein described and illustrated may be further modified toincorporate features shown in other of the embodiments.

What is claimed is:
 1. In a surgical apparatus of the type having ahandle assembly, a body portion extending from the handle assembly, atool assembly having a longitudinal axis and supported at the distal endof the body portion, and a pneumatic system located on a proximal end ofthe apparatus, the pneumatic system including a piston with a pistonhead portion disposed in a drive cylinder and adapted for application ofpneumatic force thereto, the improvement wherein said piston headportion has an elliptical configuration and is positioned within saiddrive cylinder which has opposed proximal and distal end portions and acomplementary operative elliptical transverse cross-sectionalconfiguration, the drive cylinder having a longitudinal axissubstantially parallel to the longitudinal axis of the tool assemblywherein the pistol head portion is pneumatically actuated to translatefrom the distal end portion of the drive cylinder away from the toolassembly and towards the proximal end portion of the drive cylinder andis spring biased towards the distal end portion of the drive cylinder.2. A surgical apparatus of the type having a handle assembly, a bodyportion extending distally from the handle assembly, a tool assemblyextending distally from the distal end of the body portion, an actuatingmember operatively associated with the tool assembly extending throughand movable along a longitudinal axis of the body portion, and apneumatic system located on a proximal end of the apparatus, thepneumatic system including a piston and a drive cylinder within whichthe piston translates, the drive cylinder having proximal and distal endportions, the improvement comprising the piston being pneumaticallydriven from a distal end portion of the drive cylinder in a directionsubstantially parallel to the movement of the actuating member away fromthe tool assembly towards a proximal end portion of the drive cylinder.3. A surgical apparatus as recited in claim 2, wherein the piston has apiston head having an elliptical configuration.
 4. A surgical apparatusas recited in claim 3, wherein the drive, cylinder has an ellipticalcross-sectional configuration.